Island

ABSTRACT

301,026. Menville-Jenckes Co., (Assignees of Merriman, I. B.). Nov. 23, 1927, [Convention date]. Small chambers.-Artificial silk wound on perforated tubes is dried by forcing hot air outwardly through the wound packages, the packages being contained in a drying-chamber. Thus, the tubes carrying the packages may be passed over a series of perforated pipes 24, Fig. 6, mounted in hot air chests 23, which are themselves carried by a wheeled carriage 28. The latter is run into a heated drying-chamber 27.

l. B. MERRIMAN MANUFACTURE OF RAYON Filed Nov. 25, 1927 @w L11 57mm f/Mmwy l. l l w Feb. 19, 1929.

Feb, 19, 1929. Y`

l. B. MERRIMAN MANUFACTURE OF RAYON Filed Nov. 25, 1927 2 Sheets-Sheet 2Patented Feb. 19, 1929.

UNITED STATES PATENT OFFICE.

ISAAC B. MERRIMAN, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR T MANVILLEJENCKES COMPANY, OF PAWTUCKET, RHODE ISLAND, A CORPORATION OF RHODE YISLAND.

MANUFACTURE OF RAYON.

Application iled November 23, 1927. Serial No. 235,344.

The present invention relates to rayon (artificial silk) and processesof making rayon and is intended primarily as an improvem-ent in theproduction of rayon from a viscose by the pot spinning process, althoughin certainv aspects the invention is applicable to the production ofrayon from other substances and by other spinning processes.

ln the pot spinning method of manufaclo turing rayon at present in use,a cellulose solutionA such as viscose, is precipitated in the form ofslender fibrous filaments by forc ing the solution through a spinneretinto a precipitating or setting bath. The filaments are then gatheredtogether to form a thread and the thread is guided to a centrifuge potby which it is twisted and formed into a socalled cakc. From the cake,after being removed from the pot, the thread is wound on reels to formskeins which are then subjected to a series of operations to prepare therayon for commercial use. These subscquentopera-tions on the threadWhile in skein form contribute a large part of the expense in themanufacture of rayon not only because of the time and labor required,but also because of the difficulty of handling the thread Y in this formand the Waste of material resulting from the necessarily harsh treatmentto which the skeins are subjected. The skeins, as taken from the reels,are ordinarily separated into a number of smaller skeins to preventtangling, and the skeins vso formed are usually then washed, dried, andthereafter subjected to a desulphurizing operation for removingchemicalsbrought over from the original cellulose solution. The skeins.of thread may be bleached and oiled and afteragain being dried areready for use as White or uncolored rayon. Where colored material isdesired, it is usually dyed after the last drying operation, either inthe skein or subsequent to the Weaving of the rayon into cloth.

rilhe process as described above is open to many disadvantages, not onlybecause of the expenseofmanufacture, but also because of the quantity ofWaste and inferior threadA produced. The skeins, which consist ofbundles ofV loose threads, must be carefully handled to prevent tanglingand the various solutions used for Washing, bleaching, etc., must beappliedvvith great care, either by dipping or by light spraying, inorder to prevent breaking down of the delicate fibers, secure uniformpenetration of the various treating liquids, and an even absorption ofthe dyes. Moreover, in order to impart luster to the thread, it isnecessary to stretch it during some step in the process and thisoperation is ordinarily carried out by putting the skeins under tensionduring the first drying step. vThis results in broken filaments andconsequently in the production of thread of inferior grades.

The principal object of the present invention is to devise a method forthe manufac ture of rayon which is, as compared With present daymethods, simple and inexpensive, Which results in the production ofthread of high strength and luster and uniform color, and which avoidsthebreakage of filaments at any stage in the treatment and theproduction of thread which must be graded as inferior from this cause.

Another object of the invention is to provide a package of precipitatedfiber in a condition to permit convenient and rapid operations ofbleaching, dyeing, and the like with substantially uniform effect uponall parts of the fiber and with little danger of breakage or othermechanical injury.

A still further object of the present invention is to produce rayon ofhigh strength and possessing the desirable characteristics of luster andcolor which are 4uniform throughout the product.

With these and other objects in View as Will hereinafter appear, theprincipal feature of the present invention comprises a method by Whichall operations subsequent to the gathering and twisting of the lamentsare performed upon a tightly Wound package of thread. r)he package ispreferably formed on a hollow perforated tube or spindle, the fiberbeing Wound thereon directly from the so-called cake formed in thecentrifuge pot of the spinning machine. During this Winding operation noendeavor is made to Wash the fiber or to treat it chemically, thepurpose being to Wind the thread in a closely compacted mass Which ispermeated by the solutions present in the spin ning bath. At this timealso, it is desirable to prevent drying of the thread.

fiber present in the package forms only a small percentage of the totalWeight, the re` When thev process is properly carried out, the amountof` Vsalts of precipitating bath... Y quent operations oit washing,desulphuriting, bleaching, sizing anddyeing etc. are carried mainderbeing,` made upy of water and the he subse-` out byforcing the variousliquids underpressure through the package.

Thestructure'oi" the package, due to the V fact that the liber formsonly a vsmall per` centage ofthe total weight, allows the treatingfluids readily to pass through Vthe package while sulicient resistanceis offered to the flow of; 'the liquids, insure la uniform penebysubjecting the packagee color 'and luster 4as well `for the subsequentoperati-ons of b tration ot the ii'uidsto .all parts of the threadin'ass. v'lhe'se operations are best carried out i under pressure,iiiorder that thorough conat all pants ai the thread may be ef-V fected,the compact winding of the thread preventifiig'iundue stresses en 'anyVparts thereof which V'might xteiii'dto weaken or destroy the fibers..Ait r treatment, the package is dried y suitable manner.

but preterably ialytothe heat `ofYan.ordiiriry drying"chamber 'whileforcing hot air through the `package from Q -1 c thei'nterior outwardlyso :as to quickly dryV tlieiaackw'e uniiioitniili bi subiectinc'" allparts 23 J7 .r n

treatment of the fiber with ut necessity tor. skeining for any oi2 thespecial handlingV required under existing methods. rllie package, ifkept .in a meist condition, will .retain its lproperties indefinitely.,and will aching, washing, sizing', dyeing, etc. Whenever. t is necessato Jrefofare the threadfor weavinfr C or knitting purposes.

. lnthfe accompanying drawings Fig. i isa View in 'sideelevationofa cakeafter beine" removed vfrom the centrifuge pot. Fig-."2 is a view insid-.e elevation or the package as it comes from the winding machine, aportion ofthe thread mass being broken away to show the lperforated*tube upon which the thread mass is supported. Fig, 3 is fa detail viewofaportion of an apparatus in which the packages maybe subjected to thevarious solutions employed for treatintgv the thread, illustrating themanner-in which the .packages maybe supported to enable the soluti tob'exi'orced through the packages. like.' i is a View in side-elevation:of the apparatus, a

. 'ortion owhioh is illustrated in lliozf; P e

5 is a View in fend elevati-on 'of a carri-arge forming a portion ci adrying` apparatus readyl Ydr ino' chamber into whichr .the carriao'e hasr3 v n been rolled. n The preferred torni of the invention, which fwillnow be described in detail, consists in the manufacture of rayon fromviscose. The viscose'or cellulose .solution is produced from Wood pulpor cotton linters oi a combination ef both in the usual manner. Thell'uid viscose is forced through a spinnei'et oi' any usual or preferredform into the precipitatbafth which comprises a solution of sodiumsulphate and dilute sulphuric acid. The ilaments, utter traversing a.suliiicient distance in theYpreci-pitatingibath to cause completeformation of the liber, are gathered together tol forni a thread oryarn. The yarn isV passed out of thebalth yinto a cen trituge pot of theusual -forin which rotates at a speed of several thousand revolutionsper minute, the yarn being' thrown out by centrifugal io'rce and coiledin a. cake Within the pot. A lcake formed in this manner is indicated at7 vin Fig. l. The rotation of the centrifuge pot produces the `necessarytwist for retaining the filaments in thread formation. As thus fardescribed, the process is similar to that usually carried out for ythemanufacture ofi .rayon by thc viscose method.

After the formation ort. the cake, it is removed .from the pot andthethread is wound from the cake onto a suitable support to forni avpackage. The support preferably consists ot :a hollow perforatedtu-be,such as is in dicared at'8 in Fig.. 2 in order to permit theforcing oi water or any other solutions through the package for purposesof washing, bleaching, sizing, dyeing, etc. The package woundion'awinding machineand during the universal winding operation, the yarn ismaintained under a light tension but suilicient tension to form kacompacted mass 'on the .tube as indicated at Qin Fig. 2. The solutionsof the spinning` bath which remain on the thread both in the cake' and`during the 'Winding of the package are retained thereon so that whenthe package is completed, the entire mass ot yarn is permeated .by thesolution. Tlie'cake, as formed in the centrifuge pot, vis retained in amoist condition, and the 'winding' of the package takes .place with.sufficient rapidit 1 .to prevent any appreciable evaporation olimoisture. lt is also desirable to maintain the package .in moistcondition as this prevents crystallization of the salts which wouldhavea possible injurious effect on the liber and furthermore, maintainsthe fiber as hydrocellulose rather than permitting' it to be conver edto oXycell-ulose `which has been 'found less capable `let vtaking theydye uniformly. lien completed, the package comprises only a smallproportion Iolite Weight asfiber, usualof water and the precipitatingsalts.

The package is nowv ready to be treated by the usual solutions employedfor washing, desulphurizing, bleaching, oiling, sizing, dyeing, etc. Thepackage may be kept as formed until any of these subsequent operationsare to be performed. The washing is carried out by forcing water orsuitable washing solution under pressure through the pack aga-Foruniform effect on all parts of the fiber, the washing is carried outalternately in opposite directions, from the interior of the tubeoutwardly and from the exterior of I. the tube inwardly. At theconclusion of the washing operation, the appearance of the package isnot greatly different from its appearance when first wound from thecentrifuge pot except that it is not quite so hard, although stilltightly compacted.

An apparatus by which the washing can be carried out as above describedis illustrated in Figs. 3 and l. This apparatus comprises a tank 10provided with a false bottom 11 and with a tightly fitting hinged cover12 which may be securely bolted in closed position. The false bottom 11divides the tank 10 into two chambers which communicate respectivelywith the pipes 13 and 14. Hollow perforated spindles 15 extend upwardlyfrom the false bottom 11 and are adapted to support' the perforatedtubes 8 of the thread package as indicated in Fig. 3. The spindles 15are closed at their upper ends and at their lower ends commuicate withthe chamber below the false bottom so that the washing solution can passfrom one chamber of the tank to the other' only through the perforatedspindles. The packages are supported on the spindles by conical rubberwashers indicated at 16 and these washers are arn ranged to prevent anyflow of the washing solution between the upper chamber of the tank andthe interior of the perforated spindles except through the thread mass.The washing solution is .supplied from a tank indicated at 17. This tankcommunicates through a pipe 18 with a motor driven pump 19 and vthispump is connected through a pipe 20 to a four-way valve 21. The pipes 13and 14 lead to this valve as does also a pipe 22 through which thewashing fiuid is returned to the tank 17. The pump 19 supplies thewashing solution to the valve 21 at the desired pressure and by means ofthe valve 21 the washing solution can be caused to flow altere nately inopposite directions through the pipes 13 and 14l through the packagessupported on the perforated spindles in the tank 10.

After washing, the package is subjected to the usual solutions fordesulphurizing, bleaching, oiling, sizing, dyeing, etc. the yarn. Thesesolutions may be such as are ordinarily employed in the viscose processand may be applied in the same manner as the washing solution, that isby forcing them under pressure first in one direction and then in theother through the package, by means of the apparatus illustrated inFigs. 3 and fi.

The result of the above operations may be the production of bleachedwhite rayon, which after drying7 is satisfactoryA for commerical use.Where colored rayon is desired, a dyeing operation is performed on thepackage either in addition to or in substitution for the bleachingtreatment. ln such case the dye is forced through the packagealternately from the inside outwardly and from the outside inwardlyunder pressure as in the washing, operation. Although a slight amount ofthe precipitating salts, well as some of the chemicals used fordesulphurizing, may be present in the package during the dyeingoperation, they are not detrimental at this time, but in fact have abeneficial e'ect because they act somewhat in the nature of mordants toassist inthe absorption of dye by the fiber. The dyeing step is carriedout prior to any drying of the yarn because, as previously stated, ofthe fact Vthat crystallization of a large ammini: of the salts carriedover from the precipita ing bath, is likely to detract-slightly from thehigh quality of the product. Drying of the fiber prior to dyeing, hasmoreover the disadvantage that it permits conversion of theIhydrocellulose of the yarn into oxycellir lose whichwill not return tothe hydrocellulose state if it again becomes wet. The hydrocellulose hasbeen found to have a greater and more uniform aflinity for the dye thanoxycellulose and for this reason, it is desirable to prevent conversionof the yarn into its oxycellulose condition until after the dyeingoperation. By using a suitable sizing solution the thread while in thepackage may be prepared for use as warp thread in a loom withoutsubjecting itto a separate .sizing operation as is now the practice.rlhe thread can thus be wound directly from the package on to the beamof the loom, if desired, and the use of a separate sizing and windingmechanism eliminated.

The final operation consists in drying the package. In this drying, itis desirable te subject all parts of the package simulta ncously to heatin order that the package may be dried quickly and uniformly throughoutand while under a uniform tension. As has been her inbefore suggested,this drying is preferably accomplished by forcing hot air through thepackage from the interior outwardly while subjecting the package eX-ternally to the heat of an ordinary drying chamber. An apparatus bywhich the 'packages can be conveniently dried in this manner isillustrated in Figs. 5 and 6. This apparatus comprises a cariage havinga series of horizontally arranged hollow boX Cil lll() lli) Cil

likev supports 29. Upon these supports are mounted any desired number ofperforated spindles 24,11 few only beingshown in the drawing, `similarto the spindles l'of Vthe appaiatus i'llustratedin Figs.' 3 and 4.Thesev spindles rare adapted to support the packages Whiohare to bedried in thesamel manneithat the packages are supported on the spindles15. .A pipe -connects Withthe interior of the supports 23 and this pipeis connected by a tieiriblerhoseQG to'a: source of heated air. Theheated: air is forced into the supports 23 under pressure and passesinto the spindles 24 'and then outwardly throughv the 'packages'. f Tosubject the Lenterior olf the packages to'heat simultaneously with theapplicationA oli the heat internally the carriage is run into thedryinglchamber ot, an ordinary drier indicated at 2'? in Fig.V

6 andi-or this purpose is-conveniently mounts ed upon t-he Wheelsindicated at 28.,

After drying, the package containsa loose Winding of completed'dyedf,bleached or sized thready ready for use.. Although the thread inthepackage is-in -a loosely Wound condition, it is none the less regularand AOilers no dltliculties in' univlnding.. The yarn may be Wound fromthe packagedirectly ontol quills,

bobbins, spools, or beams, suitable .for use rin- Weaving the threadinto cloth;`

lt Will be .seen that the processof the present invention eliminates the.repeated han- A Y from the centrifuge pot and containing only a smallproportion of fiber, 'forms an. im portant feature of the invention.lffthe yarn is not to be treated immediatelyor if it is de-l sired toship it to another place for treatment, the package may be easilytransportedV or kept indefinitely until such time as the furtheroperations are vto be performed@ lt is desirable to keep the package inmoist condition at all times until the final drying operation in orderVto prevent crystallization of any large quantity of the containedlsalt-sand also to maintain the liber in its hydrocelluloseconl dition. y

The nat-ure andy objects ot the invention having been indicated andthepreferred manner of. carrying out the invention having been specilicallydescribed What is claimed is:

1. rThe process of manuacturing rayon which consists in forming in aprecipitating bath a plurality 'of lilaments from a cellulose vtube to`form a compacted package consistthe package and ing ot' a smallproportion ot liberand a relatively large proportion ot Water andsubstances fromtheprecipitating bath, Washing subjecting the package tothe action eta solti on tor determining the color otthethread byforo-nig solutions throught-he package under pressure, and drying thepackage. f

2. 'lfhe process of manufacturing rayon W ich consists in 1orming in aprecipitating bath a plurality of tilamen from a cellulose solution,gatheringr the lilaments into a thread, Winding up the thread as itcomes from lthe p focipitating bath, reu'inding the wet thread* undertension onto a perforated tube to form a compacted package consistingol' a small proportion of fiber and a relatively large proportion otwater and substances 'from the precipititing bath, washing the packageandil subjecting the package to the action ot a dyeinglr solution byforcing solutions through the package under pressure'and drying thepackage.

3; The process of' manufacturing rayon which consists in 'forming in aprecipitating bath a plurality ot filaments from a cellulose solution,gathering the iilaments into a tlnfead, Winding up the thread as itcomes from the picciiitating bath, rcwinding the l Wetv thread undertension onto a perforated tube '.orin a compacted package consisting ota small proportion of fiber and a relatively large inioportion of waterandv substances from `the precipitating` bath, Washing the package andsubjcctingy the package to the action of solutions to prepare the threadtor use by forcing solutions through the package under pressure anddrying the package.

4. The process ot manufacturing rayon whichV consists in forming in aprecipitating bath a plurality of ilaments from a cellulose solution,gathering the i'ilanients into a threat., winding up the thread as itcomes from the 'areciaitatiinT bath, rewindinI the which consistsinforming in a precipitatingk bath a plurality of iilaments vfrom acellulose solution, gathering the filaments into a thread, Winding upthe thread it comes from the precipitating bath, rewinding the retthread under tension onto a perforated tube to t'orm a compacted packageconsisting et a small proportion of ber and a relatively largeproportion of water and substances from the areci ntatmfr bath Washmothe l v 2: 9 :s

package and subgectmg the package to the action of a sizing solution byforcing solutions through the package under pressure, and drying thepackage.

6. The process of manufacturing rayon which consists in forming in aprecipitating bath a plurality of filaments from a cellulose solution,gathering the filaments into a thread, twisting and winding the threadinto a cake, winding the wc thread under tension from the cake onto aperforated tube to forni a compacted package consisting of a smallproportion of liber and a relatively large proportion of water andsubstances from the precipitating bath, washing the package by forcingwater through the package under pressure and drying the package.

7. The process of manufacturing rayon which consists in making a viscosesolution, forming filaments from the viscose by precipitating it in asalt bath, gathering the lila,- ments into a thread, twisting andwinding the thread into a cake, winding the wet thread under tensionfrom the cake onto a perforated tube to form a package consisting of asmall proportion of fiber and a relatively large proportion of water anddissolved. salts, washing the package by forcing water under pressuretherethrough, and drying the package.

8. The process of manufacturing rayon from viscose which consists inprecipitating viscose in a salt bath to form a plurality of laments,gathering the filaments into a thread, twisting and winding the threadinto a cake, winding the thread while wet and containing salts from theprecipitating bath from the cake onto a perforated tube to form apackage, washing and dyeing the package by forcing solutions through thepackage under pressure, and finally drying the package.

9. The processV of manufacturing rayon from viscose which consists inwinding the 4precipitated thread without drying or other treatment intoa compacted package, washing and dyeing the package, maintaining thepackage in a moist condition until after the dyeing operation andfinally drying the packawe.

z:10. The process of preparing rayon which consists in forming aplurality of filaments from viscose in a sulphuric acid and sodium,sulphate precipitating bath, gathering the filaments into a thread,twisting the thread and winding it onto a hollow. cylinder or cake,winding the thread while moist from the cake onto a hollow perforatedtube to form a compact package consisting of a small proportion of fiberand a relatively large proportion of water and substances from theprecipitating bath, washing and dyeing the package by forcing solutionsthrough the package under pressure and finally drying the package.

l1. The process of preparing rayon which consists in forming a pluralityof filaments from viscose in a sulphuric acid and sodium sulphateprecipitating bath, gathering the filaments into a thread, twisting thethread and winding it into a hollow cylinder or cake, winding the threadwhile moist from the cake onto a hollow perforated tube to form acompact package consisting of a small proportion of fiber and arelatively large proportion of water and substances from theprecipitating bath, washing the package by forcing washing liquidsthrough the package alternately from within outwardly and from withoutinwardly, dyeing the package by forcing a dyeing solution through thepack age, maintaining the package .in a moist condition until after thedyeing operation, and finally drying the package.

12. The process of preparing rayon which consists in forming a pluralityof filaments from viscose in a sulphur-ic acid and sodium sulphateprecipitating bath, gathering the filaments into a thread, twisting thethread and winding it into a hollow cylinder or i lake", winding thethread while moist from the cake onto a hollow perforated tube to form acompact package consistingof a small proportion of fiber and arelatively large proportion of water and substances from theprecipitating bath, washing the package, subjeeting the package to theaction of solutions to prepare the thread for use and finally dry? ingthe package.

13. The process of manufacturing rayon which consists in formin a.plurality of lilaments from viscose in a sulphuric acid and sodiumsulphate precipitating bath, gathering the filaments into a thread,winding the precipitated thread while wet and containing salts from theprecipitating bath onto a perforated tube to form a package, consistingof a small proportion of libre and a relatively large proportion ofwater and dissolved salts, washing and dyeing the package by forcing`solutions through t-he package under pressure, maintaining the packagein a moist-condition Vuntil'after the dyeing operation, and finallydrying the package.

In testimony whereof l. have signed my name to this specification.

Isaac B. MERRIMAN.

